BIOC50H3 Lecture Notes - Lecture 3: Stromatolite, Archean, Proterozoic
22 Dec 2018
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3. 5 billion years ago; not 100% sure they are fossils: cyano- bacteria like cells, one evidence that do they represent actual form of life is the c13/c12 in the micro fossils suggest life. You need to build a phylogeny tree based on morphology. An alternative approach is to reconstruct phylogenetic trees of all living things, and see if it gives us clues to the common ancestor of all life. The first attempt to reconstruct the tree of life used morphological data included five kingdom scheme: prokaryotes, fungi, plants, animals, protist, obviously wrong. 2. 1 bya; oldest eukaryotes fossil: probably an alga. Looking at the actual bacterial side: oldest bacteria: cyanobacteria, left side: extant bacteria, right side: oldest type of fossil found. This helps to narrow down the line of common ancestor: about 14000 to 2100 mya: latest possible date for the split between archaea and.
